package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author lwk
 * @since 2025-6-9
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows" + userId;

        //1.判断到底是关注还是取消关注
        if (isFollow){
            //2.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSucess = save(follow);
            if (isSucess){
                //3.新增成功，把数据保存到redis中
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        }else{
            //3.取消关注，删除数据
            QueryWrapper<Follow> queryWrapper=new QueryWrapper<Follow> ();
            queryWrapper.eq("user_id",userId);
            queryWrapper.eq("follow_user_id",followUserId);
            boolean isSuccess = remove(queryWrapper);
            if (isSuccess){
                //4.删除数据，把数据从redis中移除
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }


        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        //1.查询是否关注
        Integer count = query().eq("user_id", UserHolder.getUser().getId()).eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

    //好友共同关注
    @Override
    public Result followCommons(Long id) {
        //1.获取当前登录用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows" + userId;

        //2.求交集
        String key2 = "follows" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect == null || intersect.isEmpty()){
            //3.无交集
            return Result.ok();
        }

        //4解析id集合转化为Long集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //4.1查询用户
       List<User> users = userService.listByIds(ids);
       List<UserDTO> userDTOS = BeanUtil.copyToList(users, UserDTO.class);
        return Result.ok(userDTOS);
    }
}
